Server rack with two-phase loop recirculation

Abstract

A rack with two-phase loop recirculation includes a supply manifold, a return manifold, and a separator. For example, the supply manifold is configured to receive two-phase cooling fluid from a cooling fluid source to distribute the two-phase cooling fluid to one or more server chassis. The two-phase cooling fluid is used to extract heat from one or more electronic devices and is converted into a two-phase mixture, such that at least a portion of the two-phase fluid is converted into vapor. The return manifold is configured to receive two-phase mixture fluid from one or more loops associated with one or more electronic devices in the server chassis. A separator disposed on the return manifold is configured to separate the vapor from the two-phase mixture fluid and return a first remaining portion of the two-phase cooling fluid directly to the supply manifold via the return loop.

Description

Technical Field

[0001] Embodiments of the present invention generally relate to electronic cooling, cooling hardware, two-phase liquid cooling, and rack cooling. More specifically, embodiments of the present invention relate to server racks with two-phase loop recirculation. Background Technology

[0002] Cooling, or heat removal, is a critical factor in computer system and data center design. The number of high-performance electronic components (such as high-performance processors) encapsulated within servers is steadily increasing, leading to a greater amount of heat generated and dissipated during normal server operation. If the environment in which servers operate experiences temperature increases over time, the reliability of servers used within the data center will decrease. Maintaining a suitable thermal environment is crucial for the proper operation, performance, and lifespan of these servers in the data center. This necessitates more efficient and effective cooling or heat removal solutions, especially when cooling these high-performance servers.

[0003] Previous solutions for two-phase coolants did not take into account the separation of the mixed vapor and liquid phases in the loop. These solutions were inefficient for high-power applications. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] To this end, embodiments of the present invention provide an electronic rack comprising: a supply manifold for receiving a two-phase cooling fluid from a cooling fluid source to distribute the two-phase cooling fluid to one or more server chassis, each of the server chassis containing one or more electronic devices, wherein the two-phase cooling fluid is used to extract heat from the one or more electronic devices and convert it into a two-phase mixture, such that at least a portion of the two-phase fluid is converted into vapor; a return manifold for receiving the two-phase mixture from one or more loops associated with the one or more electronic devices of the server chassis; and a first separator disposed on the return manifold to separate the vapor of the two-phase mixture and transfer a first remaining two-phase cooling fluid of the two-phase mixture back to the supply manifold via a first return loop.

[0006] In some embodiments, the electronic rack further includes a three-way valve disposed on the supply manifold and connected to the first separator to regulate the flow rate of a first residual two-phase fluid of the two-phase mixture returning to the supply manifold.

[0007] In some embodiments, when the three-way valve is configured in a first position, the two-phase cooling fluid is allowed to flow from the cooling fluid source to the server chassis, and wherein, when the three-way valve is configured in a second position, the first remaining two-phase cooling fluid is circulated back to the server chassis via the supply manifold.

[0008] In some embodiments, the electronic rack further includes a fluid level sensor disposed within the first separator to measure the fluid level within the first separator and adjust the flow rate of the three-way valve and the first remaining two-phase cooling fluid returning to the supply manifold based on the fluid level.

[0009] In some embodiments, when the fluid level is above a predetermined fluid threshold, the three-way valve is configured to manage the first remaining two-phase cooling fluid to circulate from the first separator back to the supply manifold.

[0010] In some embodiments, the electronic rack also includes a pump coupled to the supply manifold to drive the two-phase cooling fluid from the cooling fluid source and the first remaining two-phase cooling fluid from the two-phase mixed fluid from the first separator.

[0011] In some embodiments, the electronic rack further includes a second separator disposed on the return manifold to separate steam from the two-phase mixture returning from the second server chassis and to return a second residual cooling fluid to the supply manifold via a second return loop, while the first separator is used to separate steam from the two-phase mixture returning from the first server chassis.

[0012] In some embodiments, one or more server chassis having one or more server return loops are located between the first separator and the second separator, wherein the second separator receives at least a portion of the liquid from the first separator.

[0013] In some embodiments, the second separator is used to return the second remaining two-phase cooling fluid to a portion of the supply manifold via the second return loop between the first server chassis and the second server chassis.

[0014] In some embodiments, the electronic rack further includes a third separator disposed on the return manifold to separate residual cooling fluid from the two-phase mixture and return a third residual cooling fluid to the supply manifold via a third return loop, wherein the third separator is located at the bottom of the return manifold.

[0015] In some embodiments, the third return loop is connected between the inlet side of the main pump and the third separator.

[0016] Embodiments of the present invention also provide a data center cooling system, comprising: a fluid supply line connected to receive cooling fluid from a cooling fluid source; a fluid return line connected to return the cooling fluid to the cooling fluid source; and a plurality of electronic racks according to any one of the above embodiments, the plurality of electronic racks being connected to the fluid supply line and the fluid return line. Attached Figure Description

[0017] Embodiments of the invention are shown by way of example rather than limitation in the figures, wherein similar markings indicate similar elements.

[0018] Figure 1 An example design for two-phase loop recirculation according to an embodiment of this application is shown.

[0019] Figure 2 Another example design for two-phase loop recirculation according to an embodiment of this application is shown.

[0020] Figure 3 Additional example designs for two-phase loop recirculation according to embodiments of this application are shown.

[0021] Figure 4 An example of server rack hardware according to an embodiment of this application is shown.

[0022] Figure 5 An example implementation of a server rack with two-phase loop recirculation according to an embodiment of this application is shown.

[0023] Figure 6 An example of a system control flowchart for a server rack with two-phase loop recirculation according to an embodiment of this application is shown.

[0024] Figure 7 This is a block diagram illustrating an example of an electronic rack according to one embodiment. Detailed Implementation

[0025] Various embodiments and aspects of the invention will be described with reference to the details discussed below, and the accompanying drawings will illustrate the various embodiments. The following description and drawings are illustrative of the invention and should not be construed as limiting the invention. Numerous specific details are described to provide a thorough understanding of various embodiments of the invention. However, in some cases, well-known or conventional details have not been described in order to provide a concise discussion of embodiments of the invention.

[0026] The reference to "an embodiment" or "an embodiment" in the specification means that a particular feature, structure, or characteristic described in connection with that embodiment may be included in at least one embodiment of the invention. The phrase "in an embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment.

[0027] This disclosure aims to provide an advanced server rack two-phase coolant management and recirculation design for high power density servers, which are directly or indirectly designed with a two-phase cooling-based thermal management solution. Furthermore, this disclosure includes the following features and functions: an efficient design that is easy to implement; significantly increased server operating efficiency; improved IDC cooling efficiency; a highly compatible design that can be used with existing rack and server configurations; improved two-phase coolant management; vapor separation for better cooling efficiency; and feasibility with different two-phase-based thermal management systems.

[0028] This application relates to a server rack thermal recirculation design for operating a two-phase coolant. For example, the system design includes a separator that separates the two-phase mixed fluid. In embodiments, the separator allows vapor to be released from the loop (e.g., a return path) and allows the liquid to be extracted to be returned directly to the loading (e.g., a supply path). Furthermore, the system includes valves to control the activation of the returned liquid and is equipped with a supply side having at least one pump that pushes the fluid to each of the individual servers. Additionally, a fluid level sensor is used to regulate the valves, and the mass flow rate of the fluid is measured to control the overall coolant recirculation. It should be noted that all components of the server rack are fully integrated in recirculation manifolds with different embodiments to configure different systems.

[0029] According to one aspect, according to an embodiment, an electronic rack with two-phase loop recirculation includes a supply manifold, a return manifold, and a first separator. For example, according to an embodiment, an electronic rack with two-phase loop recirculation includes a supply manifold configured to receive two-phase cooling fluid from a cooling fluid source to distribute the two-phase cooling fluid to one or more server chassis. Furthermore, each of the server chassis contains one or more electronic devices, such as one or more servers. Additionally, the two-phase cooling fluid is used to extract heat from one or more electronic devices and is converted into a two-phase mixed fluid, causing at least a portion of the two-phase fluid to evaporate into vapor.

[0030] In one embodiment, the electronic rack with two-phase loop recirculation includes a return manifold to receive two-phase mixed fluid from one or more loops associated with one or more electronic devices of the server chassis. In another embodiment, the electronic rack with two-phase loop recirculation includes a first separator disposed on the return manifold to separate vapors of the two-phase mixed fluid and to transfer a first residual two-phase cooling fluid of the two-phase mixed fluid back to the supply manifold via a first direct return loop.

[0031] In one embodiment, the electronic rack with two-phase loop recirculation includes a three-way valve disposed on the supply manifold and connected to a first separator to regulate the flow rate of a first residual two-phase fluid of the two-phase mixed fluid returning to the supply manifold. Furthermore, according to one embodiment, the three-way valve is configured in a first position, allowing the two-phase cooling fluid to flow from a cooling fluid source to the server chassis. Additionally, according to another embodiment, when the three-way valve is configured in a second position, the first residual two-phase cooling fluid is circulated back to the server chassis through the supply manifold.

[0032] In one embodiment, the electronic rack with two-phase loop recirculation includes a fluid level sensor disposed within a first separator to sense the fluid level within the first separator and to adjust the flow rate of a three-way valve and a first residual two-phase cooling fluid returning to the supply manifold based on the fluid level. Furthermore, according to an embodiment, when the fluid level is above a predetermined fluid threshold, the three-way valve is configured to allow the first residual two-phase cooling fluid to circulate from the first separator back to the supply manifold.

[0033] In one embodiment, the electronic rack with two-phase loop recirculation includes a pump coupled to a supply manifold to drive a first residual two-phase cooling fluid from a cooling fluid source and a two-phase mixed fluid from a first separator.

[0034] According to another embodiment, the electronic rack with two-phase loop recirculation further includes a second separator disposed on the return manifold to separate steam from the two-phase mixed fluid returning from the second server chassis and to return a second residual cooling fluid to the supply manifold via the second return loop, while the first separator is used to separate steam from the two-phase mixed fluid returning from the first server chassis. Further, according to an embodiment, the first server chassis is located above the second server chassis, and the first separator is also used to receive at least the steam generated by the second server chassis from the second separator. Additionally, according to an embodiment, the second separator is used to return a portion of the second residual two-phase cooling fluid to the supply manifold via a second return loop between the first and second server chassis.

[0035] According to another embodiment, the electronic rack with two-phase loop recirculation further includes a third separator, which is disposed on the return manifold to separate the remaining cooling fluid from the two-phase mixture and return the remaining cooling fluid to the supply manifold via the third return loop. Furthermore, according to an embodiment, the third return loop is connected between the inlet side of the main pump and the third separator. Additionally, according to an embodiment, the third separator is located at the bottom of the return manifold.

[0036] According to another embodiment, the data center cooling system includes a fluid supply line, a fluid return line, and multiple electronic racks connected to the fluid supply line and the fluid return line. For example, according to an embodiment, the data center cooling system includes a fluid supply line connected to receive cooling fluid from a cooling fluid source. Furthermore, according to an embodiment, the data center cooling system includes a fluid return line connected to return the cooling fluid to the cooling fluid source. Additionally, according to an embodiment, the data center cooling system includes multiple electronic racks connected to the fluid supply line and the fluid return line.

[0037] In embodiments, each of the plurality of electronic racks includes a supply manifold, a return manifold, and a first separator. For example, according to an embodiment, an electronic rack with two-phase loop recirculation includes a supply manifold configured to receive two-phase cooling fluid from a cooling fluid source to distribute the two-phase cooling fluid to one or more server chassis. Furthermore, each of the server chassis contains one or more electronic devices, such as one or more servers. Additionally, the two-phase cooling fluid is used to extract heat from one or more electronic devices and is converted into a two-phase mixed fluid, such that at least a portion of the two-phase fluid is converted into vapor.

[0038] Figure 1 An example design 100 of a server rack with two-phase loop recirculation according to an embodiment of this application is shown. Specifically, Figure 1 A system design 100 including a separator 101 is shown, which is designed to be disposed on a return loop 103. The separator 101 can be disposed in different locations. In an embodiment, the separator 101 is used to separate a two-phase cooling fluid in liquid form from its gaseous phase. In this example, when the separator 101 is vertically assembled in the system, vapor 117 can escape and continue to rise through a vapor loop (e.g., return manifold 113), while at least a portion of the cooling fluid in liquid form is transferred back to the supply side, i.e., supply manifold 111, via the return loop or path 103.

[0039] In one embodiment, the server rack design 100 with two-phase loop recirculation includes a separator 101 directly connected to a return loop 103 to return the liquid flow to a supply 111 (e.g., a supply manifold). Figure 1 In the illustrated design, the three-way valve 107 is used to regulate the fluid. Furthermore, according to an embodiment, a pump 109 powers the fluid flow on the supply manifold 111, and the pump 109 pumps cooling fluid from the source 119 and returns the flow (if the valve 117 is open). Alternatively, according to an embodiment, mass flow rate data 121 is collected from the source 119 for controlling the opening ratio of the valve 117, which can be utilized by a controller (not shown) for further control of the valve 117 thereafter.

[0040] Furthermore, according to an embodiment, a fluid level sensor 105 is used within the separator 101, and the sensor 105 is used to regulate the flow rate of the three-way valve 117 and the return flow back to the supply 111 (e.g., the supply manifold). For example, according to an embodiment, the return loop 103 is activated only if the fluid level is above the return loop port or above a predetermined threshold. According to an embodiment, this is to ensure that minimal or no steam is directly returned to the supply 111 (e.g., the supply manifold).

[0041] Furthermore, according to an embodiment, each server loop is designed to be located below the separator (e.g., separator 101). Additionally, according to an embodiment, a pump (e.g., pump 109) is used to pump fluid recirculated to the servers (e.g., 115a, 115b, 115c).

[0042] In one embodiment, the electronic rack 100 with two-phase loop recirculation includes a supply manifold 111, a return manifold 113, and a first separator 101. For example, according to one embodiment, the electronic rack 100 with two-phase loop recirculation includes a supply manifold 111 configured to receive two-phase cooling fluid from a cooling fluid source 119 to distribute the two-phase cooling fluid to one or more server chassis (e.g., 115a, 115b, 115c). Furthermore, according to one embodiment, each of the server chassis (e.g., 115a, 115b, 115c) is configured to contain one or more electronic devices, such as one or more servers. Additionally, according to one embodiment, the two-phase cooling fluid is used to extract heat from one or more electronic devices (e.g., 115a, 115b, 115c) and convert it into a two-phase mixed fluid, such that at least a portion of the two-phase fluid is converted into steam (e.g., 117).

[0043] In one embodiment, the electronic rack 100 with two-phase loop recirculation includes a return manifold 113 configured to receive a two-phase mixed fluid from one or more loops (e.g., 123a, 123b, 123c) associated with one or more electronic devices in a server chassis (e.g., 115a, 115b, 115c).

[0044] In one embodiment, the electronic rack 100 with two-phase loop recirculation includes a first separator 101 disposed on a return manifold 113 to separate the vapor 117 of the two-phase mixed fluid and to transfer the first remaining two-phase cooling fluid of the two-phase mixed fluid back to the supply manifold 111 via the first return loop 103.

[0045] In one embodiment, the electronic rack 100 with two-phase loop recirculation includes a three-way valve 107 configured to be disposed on a supply manifold 111 and connected to a first separator 101 to regulate the flow rate of a first residual two-phase fluid of the two-phase mixed fluid returning to the supply manifold 111. Furthermore, according to an embodiment, the three-way valve 107 is configured in a first position, allowing the two-phase cooling fluid to flow from the cooling fluid source 119 to the server chassis (e.g., 115a, 115b, 115c) through one or more loops (e.g., 125a, 125b, 125c). Furthermore, according to an embodiment, when the three-way valve 107 is configured in a second position, the first residual two-phase cooling fluid is circulated back to the server chassis (e.g., 115a, 115b, 115c) via the supply manifold 111.

[0046] In one embodiment, the electronic rack 100 with two-phase loop recirculation includes a fluid level sensor 105 configured to be disposed within a first separator 101 to sense the fluid level within the first separator 101 and to adjust the flow rate of a three-way valve 107 and a first residual two-phase cooling fluid returning to the supply manifold 111 based on the fluid level. Furthermore, according to an embodiment, when the fluid level is above a predetermined fluid threshold, the three-way valve 107 is configured to allow the first residual two-phase cooling fluid to circulate from the first separator 101 back to the supply manifold 111.

[0047] In one embodiment, the electronic rack 100 with two-phase loop recirculation includes a pump 109 connected to a supply manifold 111 to pump a first residual two-phase cooling fluid from a cooling fluid source 119 and a two-phase mixed fluid from a first separator 101.

[0048] Figure 2 Another example design 200 of a server rack with two-phase loop recirculation according to an embodiment of this application is shown. Specifically, Figure 2Another design 200 is shown, according to an embodiment, using more than one separator (e.g., 201, 211) in the system to enhance the ability to separate two-phase mixed flows. It can be seen that, according to the embodiment, each return loop (e.g., return loops 207, 217) is designed with a control valve (e.g., 205, 215) and a pump (e.g., 203, 213). The control valves and pumps can be controlled by a controller (e.g., a microcontroller, not shown). Furthermore, according to the embodiment, both components are used to regulate the returned flow.

[0049] Furthermore, according to an embodiment, the servers (e.g., 209, 219a, 219b, 219c) are located below (e.g., 219) or between (e.g., 209) the separators (e.g., 201, 211). Additionally, according to an embodiment, liquid flow can accumulate within the separators (e.g., 201, 211). In this design, according to an embodiment, each of the source loop 111 (e.g., a supply manifold) and the two return loops (e.g., 207, 217) is assembled with a pump (e.g., 203, 213). Alternatively, according to an embodiment, the server chassis 209 can be understood as one or more servers.

[0050] In an embodiment, the electronic rack 200 with two-phase loop recirculation includes a supply manifold 111, a return manifold 113, a first separator 201, and a second separator 211. For example, according to an embodiment, the electronic rack 200 with two-phase loop recirculation includes a supply manifold 111 configured to receive two-phase cooling fluid from a cooling fluid source to distribute the two-phase cooling fluid to one or more server chassis (e.g., 209, 219a, 219b, 219c). Furthermore, according to an embodiment, each of the server chassis (e.g., 209, 219a, 219b, 219c) is configured to contain one or more electronic devices, such as one or more servers. Additionally, according to an embodiment, the two-phase cooling fluid is used to extract heat from one or more electronic devices (e.g., 209, 219a, 219b, 219c) and convert it into a two-phase mixed fluid, such that at least a portion of the two-phase fluid is converted into vapor.

[0051] In one embodiment, the electronic rack 200 with two-phase loop recirculation includes a return manifold 113 configured to receive two-phase mixed fluid from one or more loops (e.g., 223, 123a, 123b, 123c) associated with one or more electronic devices in a server chassis (e.g., 209, 219a, 219b, 219c).

[0052] In one embodiment, the electronics rack 200 with two-phase loop recirculation includes a first separator 201 disposed on a return manifold 113 to separate the vapor of the two-phase mixture and transfer a first residual two-phase cooling fluid of the two-phase mixture back to the supply manifold 111 via a first return loop 207. In another embodiment, the electronics rack 200 with two-phase loop recirculation includes a pump 221 coupled to the supply manifold 111 to pump two-phase cooling fluid from a cooling fluid source, a first residual two-phase cooling fluid from the two-phase mixture of the first separator 201, and a second residual two-phase cooling fluid from the two-phase mixture of the second separator 211.

[0053] In one embodiment, the electronic rack 200 with two-phase loop recirculation further includes a second separator 211 disposed on the return manifold 113 to separate steam from the two-phase mixed fluid returning from the second server chassis (e.g., 219a, 219b, 219c) and return a second residual cooling fluid to the supply manifold 111 via a second return loop 217, while a first separator 201 is used to separate steam from the two-phase mixed fluid returning from the first server chassis 209. Furthermore, according to another embodiment, the first server chassis 209 is located above the second server chassis (e.g., 219a, 219b, 219c), and the first separator 201 is also configured to receive at least the steam generated by the second server chassis (e.g., 219a, 219b, 219c) from the second separator 211. Furthermore, according to an embodiment, the second separator 211 is used to return the second remaining two-phase cooling fluid to a portion of the supply manifold via a second return loop 217 between the first server chassis 209 and the second server chassis 219.

[0054] Figure 3 An example design 300 of a server rack with two-phase loop recirculation according to an embodiment of this application is shown. Specifically, Figure 3 Design 300 is shown, in which a server rack with a two-phase loop recirculation system includes multiple separators (e.g., 301, 311) and one of the separators (e.g., 311) is designed at the bottom of the rack hardware. According to an embodiment, this design 300 considers one of the best designs for separating liquid from a two-phase mixed flow, and the return loop (e.g., 307, 317) is directly connected to the inlet side of a main pump that is integrated with the main source (e.g., 319).

[0055] Furthermore, it can be seen that the above Figures 1 to 3Different system designs (e.g., 100, 200, 300) are shown, with different configurations of return loops, pump and valve combinations, and separator designs. Furthermore, the key mechanism remains the same: according to the embodiments, the two-phase coolant is separated into the recirculation loop and the liquid is effectively recirculated.

[0056] In an embodiment, the electronic rack 300 with two-phase loop recirculation includes a supply manifold 111, a return manifold 113, a separator 301, and a separator 311. For example, according to an embodiment, the electronic rack 300 with two-phase loop recirculation includes a supply manifold 111 configured to receive two-phase cooling fluid from a cooling fluid source 319 to distribute the two-phase cooling fluid to one or more server chassis (e.g., 309, 319a, 319b, 319c). Furthermore, according to an embodiment, each of the server chassis (e.g., 309, 319a, 319b, 319c) is configured to contain one or more electronic devices, such as one or more servers. Additionally, according to an embodiment, the two-phase cooling fluid is used to extract heat from one or more electronic devices (e.g., 309, 319a, 319b, 319c) and convert it into a two-phase mixed fluid, such that at least a portion of the two-phase fluid is converted into vapor.

[0057] In one embodiment, the electronic rack 300 with two-phase loop recirculation includes a return manifold 113 configured to receive two-phase mixed fluid from one or more loops (e.g., 323, 123a, 123b, 123c) associated with one or more electronic devices in a server chassis (e.g., 309, 319a, 319b, 319c).

[0058] In one embodiment, the electronic rack 300 with two-phase loop recirculation includes a separator 301 disposed on the return manifold 113 to separate the vapor of the two-phase mixture and to transfer the first remaining two-phase cooling fluid of the two-phase mixture back to the supply manifold 111 via the first return loop 307.

[0059] In one embodiment, the electronic rack 300 with two-phase loop recirculation includes a pump 315 connected to a supply manifold 111 to pump a two-phase cooling fluid from a cooling fluid source, a first residual two-phase cooling fluid from a two-phase mixed fluid from a separator 301, and a second residual two-phase cooling fluid from a two-phase mixed fluid from a separator 311.

[0060] In one embodiment, the electronic rack 300 with two-phase loop recirculation further includes a separator 311 configured on the return manifold 113 to separate residual cooling fluid from the two-phase mixture and return a third residual cooling fluid to the supply manifold 111 via a third return loop 307. Furthermore, according to one embodiment, the third return loop 307 is configured to connect between the inlet side of the main pump 315 and the separator 311. Additionally, according to one embodiment, the separator 311 is located at the bottom of the return manifold 113. The separator 311 can function as a fluid collector to collect any cooling fluid dripping downwards through the return manifold 113 and return the collected cooling fluid directly to the supply manifold 111 via the return loop 317, while the return manifold 113 allows vapor to rise upwards for eventual processing by the condenser.

[0061] Figure 4 An example of server rack hardware 400 according to an embodiment of this application is shown. Specifically, Figure 4 A server rack with a two-phase loop recirculation system according to an embodiment is shown, entirely built on rack hardware 400 such as a rack distribution manifold. Furthermore, according to an embodiment, the manifold (e.g., 111, 113) includes a supply side 111 (e.g., a supply manifold) and a return side 113 (e.g., a return manifold). For example, according to an embodiment, a separator (e.g., 401) is built on the return side 113 (e.g., the return manifold). According to an embodiment, in this design 400, control valves 403 and pumps (e.g., 405), as well as sensors, are all encapsulated on manifold 111 (e.g., the supply manifold). Furthermore, manifold 111 is vertically mounted to the rack, and systems shown in previous figures (e.g., 100, 200, 300) can be integrated into the manifold (e.g., 111) for different scenarios.

[0062] For the purpose of distributing cooling fluid to the server chassis and receiving cooling fluid returning from the server chassis, the connectors on the supply manifold 111 and return manifold 113 can be used to connect with corresponding server mating connectors. The connectors can be blind-mating, drip-free connectors that automatically connect when the server chassis is pushed toward the supply and return manifolds.

[0063] Figure 5 An example implementation of a server rack 500 with two-phase loop recirculation according to an embodiment of this application is shown. Specifically, Figure 5 A rack-level integrated design 500 according to an embodiment is shown, which includes a manifold with fluid separation and regulating built-in hardware features.

[0064] Furthermore, according to an embodiment, the rack 500 may also include a condenser unit 501, which is used to condense steam and is connected to the supply of a manifold (e.g., supply manifold 111). Additionally, according to an embodiment, the condenser 501 and the support manifolds (e.g., 111, 113) may be directly connected to the system steam line and liquid line.

[0065] Figure 6 An example of a system control flowchart 600 for a server rack with two-phase loop recirculation according to an embodiment of this application is shown. Specifically, Figure 6 A flowchart illustrating key control features using sensors according to embodiments of this application is shown. For example, according to an embodiment, a key aspect of this disclosure is the direct control of the return loop and the elimination of vapor in the mixed fluid to directly transfer the first remaining two-phase cooling fluid of the two-phase mixed fluid back to the supply manifold via a first return loop. Furthermore, according to an embodiment, all features are integrated into a rack-based unit.

[0066] In an embodiment, during operation 601, a sensor (e.g., 105) measures the fluid level within a separator (e.g., 101, 201, 211, 301, 311), and the sensor measures the mass flow rate (e.g., 121).

[0067] Furthermore, according to an embodiment, in operation 603, sensors measure the temperature of each server (e.g., 115, 209, 219a, 219b, 219c, 309, 319a, 319b, 319c). Additionally, in operation 605, if the mass flow rate (e.g., 121) needs to be increased, and then, in operation 607, if the fluid level within the separators (e.g., 101, 201, 211, 301, 311) is higher than a default value, then, in operation 609, the system will adjust control valves (e.g., 107, 205, 215, 303, 313) to allow liquid in the return manifold (e.g., 113) to flow directly through the return loop (e.g., 103, 207, 217, 307, 317). It should be noted that, according to the embodiment, the system control flowchart 600 of the server rack with two-phase loop recirculation is used as an example to illustrate one of the operations of the unit, and the key concept is to manage the direct liquid fluid flowing from the return manifold 113 back to the supply manifold 111 using the fluid level (e.g., a predetermined fluid level) within the separator measurement value.

[0068] Figure 7This is a block diagram illustrating an electronic rack according to one embodiment. Electronic rack 1200 may represent any electronic rack described throughout this application. According to one embodiment, electronic rack 1200 includes, but is not limited to, a heat exchanger 1211, a rack management unit (RMU) 1202, and one or more server chassis 1203A-1203E (collectively referred to as server chassis 1203). Server chassis 1203 may be inserted from either the front end 1204 or the rear end 1205 of electronic rack 1200 into an array of server slots (e.g., standard racks). Each server chassis may include one or more blade slots to receive one or more blade servers. Each blade server represents one or more of these servers.

[0069] It should be noted that although five server chassis 1203A-1203E are shown here, more or fewer server chassis may be housed within the electronic rack 1200. It should also be noted that the specific locations of the heat exchanger 1211, RMU 1202, and / or server chassis 1203 are shown for illustrative purposes only; other arrangements or configurations of the heat exchanger 1211, RMU 1202, and / or server chassis 1203 may also be implemented. In one embodiment, the electronic rack 1200 may be open to the environment or partially contained within a rack container, provided that cooling fans can generate airflow from front to rear.

[0070] In addition, for at least some of the server chassis 1203, optional fan modules (not shown) are associated with the server chassis. Each fan module includes one or more cooling fans. The fan modules may be mounted on the rear end or electronic rack of the server chassis 1203 to generate airflow that flows from the front end 1204, travels through the air space of the server chassis 1203, and exits at the rear end 1205 of the electronic rack 1200.

[0071] In one embodiment, heat exchanger 1211 may be a liquid-to-liquid heat exchanger. Heat exchanger 1211 includes a first loop having an inlet port and an outlet port, the inlet and outlet ports having a first pair of liquid connectors, the first pair of liquid connectors being coupled to external liquid supply / return lines 1231-1232 to form a main loop. The connectors coupled to the external liquid supply / return lines 1231-1232 may be provided or mounted on the rear end 1205 of the electronics rack 1200. Liquid supply / return lines 1231-1232, also referred to as indoor liquid supply / return lines, may be coupled to an external cooling system.

[0072] In addition, heat exchanger 1211 includes a second loop with two ports having a second pair of liquid connectors coupled to rack manifold 1225 to form a secondary loop. The secondary loop may include a supply manifold (also referred to as a rack liquid supply line or rack supply manifold) to supply coolant to server chassis 1203 and a return manifold (also referred to as a rack liquid return line or rack return manifold) associated with one or more separators to return hotter liquid to heat exchanger 1211. It should be noted that heat exchanger 1211 can be any kind of commercially available or custom-made heat exchanger. Therefore, details of heat exchanger 1211 will not be described here.

[0073] Each server chassis 1203 may include one or more information technology (IT) components (e.g., electronic devices such as processors, memory, and / or storage devices). In one embodiment, in at least some of the server chassis 1203, the electronic devices may be attached to a cold plate. The cold plate includes liquid distribution channels to receive cooling liquid from the rack liquid supply lines of the rack manifold 1225. The cooling liquid exchanges heat with heat generated from the electronic devices attached to the cold plate. The cooling liquid carrying the exchanged heat is returned to the rack liquid return lines of the rack manifold 1225 and then back to the heat exchanger 1211.

[0074] In another embodiment, some server chassis 1203 may include an immersion tank containing an immersion coolant. The electronics of the respective server are at least partially immersed in the immersion coolant. The immersion coolant may be a dielectric coolant that circulates between the immersion tank and heat exchanger 1211. The coolant may be a single-phase coolant or a two-phase coolant (also known as a phase-change coolant). When the temperature of the coolant is above a predetermined temperature threshold (e.g., the boiling point of the coolant), the two-phase coolant evaporates from liquid form into vapor form. The vapor flows upstream from the respective server chassis to the heat exchanger 1211 via vapor lines associated with one or more separators. The heat exchanger 1211 may include a condenser to condense the vapor back from vapor form to liquid form, wherein the coolant is then supplied back to the server chassis.

[0075] It should be noted that some server chassis 1203 may be configured with single-phase liquid cooling, while other server chassis may be configured with two-phase liquid cooling. Even within a single server chassis, some IT components may be configured with single-phase liquid cooling, while others may be configured with two-phase liquid cooling. Rack manifold 1225 may include a first rack manifold for single-phase cooling and a second rack manifold for two-phase cooling, to be connected to the same or different server chassis for different types of cooling. Some server chassis 1203 may be configured with conventional liquid and air cooling, while other server chassis may be configured with immersion cooling.

[0076] Some IT components can perform data processing tasks, which may include software installed on machine-readable media such as storage devices, loaded into memory, and executed by one or more processors to perform data processing tasks. Server chassis 1203 may include host servers (referred to as host nodes) connected to one or more compute servers (also referred to as compute nodes). The host server (having one or more central processing units or CPUs) typically interfaces with clients via a network (e.g., the Internet) to receive requests for specific services such as storage services (e.g., cloud-based storage services like backup and / or recovery), execute applications to perform certain operations (e.g., image processing, deep data learning algorithms, or modeling, as part of a Software as a Service or SaaS platform). In response to the request, the host server assigns the task to one or more compute nodes or compute servers (having one or more graphics / general-purpose processing units or GPUs) managed by the host server. The compute servers perform the actual tasks, which may generate heat during operation.

[0077] The electronics rack 1200 also includes an optional RMU 1202, which is configured to provide and manage power supplied to the server 1203 and the heat exchanger 1211. The RMU 1202 can be coupled to a power supply unit (not shown) to manage the power consumption of the power supply unit. The power supply unit may include necessary circuitry (e.g., an AC-to-DC or DC-to-DC power converter, a battery, a transformer, or a regulator, etc.) to provide power to at least some of the remaining components of the electronics rack 1200.

[0078] In one embodiment, the RMU 1202 includes an optional optimization module 1221 and a rack management controller (RMC) 1222. The RMC 1222 may include a monitor to monitor the operational status of various components within the electronic rack 1200, such as compute nodes 1203, heat exchangers 1211, and fan modules. Specifically, the monitor receives operational data representing the operating environment of the electronic rack 1200 from various sensors. For example, the monitor may receive operational data representing the temperature of the processor, coolant, and airflow, which may be captured and collected via various temperature sensors. The monitor may also receive data representing fan power and pump power generated by one or more fan modules and liquid pumps, which may be proportional to their respective speeds. This operational data is referred to as real-time operational data. It should be noted that the monitor may be implemented as a separate module within the RMU 1202.

[0079] Based on the operating data, the optimization module 1221 uses a predetermined optimization function or model to derive a set of optimal fan speeds for the fan module and an optimal pump speed for the liquid pump, minimizing the total power consumption of the liquid pump and fan module while keeping the operating data associated with the cooling fans of the liquid pump and fan module within their respective design specifications. Once the optimal pump speed and optimal fan speed have been determined, the RMC 1222 configures the cooling fans of the liquid pump and fan module based on these optimal speeds.

[0080] In the foregoing description, embodiments of the invention have been described with reference to specific exemplary embodiments. It will be apparent that various modifications can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. Therefore, the description and drawings should be considered illustrative rather than restrictive.

Claims

1. An electronic rack, comprising: A supply manifold for receiving two-phase cooling fluid from a cooling fluid source to distribute the two-phase cooling fluid to one or more server chassis, each of the server chassis containing one or more electronic devices, wherein the two-phase cooling fluid is used to extract heat from the one or more electronic devices and convert it into a two-phase mixed fluid, such that at least a portion of the two-phase fluid is converted into steam; A return manifold, the return manifold being used to receive the two-phase mixed fluid from one or more loops associated with one or more electronic devices of the server chassis; and A first separator is vertically disposed on the return manifold to separate the vapor of the two-phase mixture and to transfer the first remaining two-phase cooling fluid of the two-phase mixture back to the supply manifold via a first return loop; A third separator is disposed on the return manifold to separate the remaining cooling fluid from the two-phase mixture and return the third remaining cooling fluid to the supply manifold via a third return loop, wherein the third separator is located at the bottom of the return manifold.

2. The electronic rack according to claim 1, further comprising: A three-way valve is disposed on the supply manifold and connected to the first separator to regulate the flow rate of the first remaining two-phase fluid of the two-phase mixture returning to the supply manifold.

3. The electronic rack according to claim 2, wherein, When the three-way valve is configured in the first position, the two-phase cooling fluid is allowed to flow from the cooling fluid source to the server chassis, and wherein, when the three-way valve is configured in the second position, the first remaining two-phase cooling fluid is circulated back to the server chassis via the supply manifold.

4. The electronic rack according to claim 2, further comprising: A fluid level sensor is disposed within the first separator to measure the fluid level within the first separator and, based on the fluid level, adjust the flow rate of the three-way valve and the first remaining two-phase cooling fluid returning to the supply manifold.

5. The electronic rack according to claim 4, wherein, When the fluid level is above a predetermined fluid threshold, the three-way valve is configured to manage the first remaining two-phase cooling fluid to circulate from the first separator back to the supply manifold.

6. The electronic rack according to claim 1, further comprising: A pump connected to the supply manifold to drive the two-phase cooling fluid from the cooling fluid source and the first remaining two-phase cooling fluid from the two-phase mixed fluid from the first separator.

7. The electronic rack according to claim 1, further comprising: A second separator is provided on the return manifold to separate steam from the two-phase mixture returning from the second server chassis and to return a second residual cooling fluid to the supply manifold via a second return loop, while the first separator is used to separate steam from the two-phase mixture returning from the first server chassis.

8. The electronic rack according to claim 7, wherein, One or more server chassis with one or more server return loops are located between the first separator and the second separator, wherein the second separator receives at least a portion of the liquid from the first separator.

9. The electronic rack according to claim 8, wherein, The second separator is used to return the second remaining two-phase cooling fluid to a portion of the supply manifold via the second return loop between the first server chassis and the second server chassis.

10. The electronic rack according to claim 1, wherein, The third return loop is connected between the inlet side of the main pump and the third separator.

11. A data center cooling system, comprising: A fluid supply line is connected to receive cooling fluid from a cooling fluid source; A fluid return line is connected to return the cooling fluid to the cooling fluid source; Multiple electronic racks according to any one of claims 1-10, wherein the multiple electronic racks are coupled to the fluid supply line and the fluid return line.

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